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    19316 research outputs found

    Survival analysis of osteosarcoma patients: A 15-year experience

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    Introduction: Management of osteosarcoma has evolved considerably for the past two decades and there have been changes of practices especially pertaining to chemotherapy regime. This is a review of our cases in the past 15 years. Method: This is a retrospective survival analysis study of 128 patients treated at University Malaya Medical Centre (UMMC) from 1997 to 2011. Results: There were 80 (62.5%) male and 48 (37.5%) female patients with the median age being 15 (5–59). Majority had osteosarcoma of extremities (94.5%). More than 60% patients developed metastasis throughout the course of treatment with 39% presenting with lung metastasis. Osteoblastic osteosarcoma was the commonest subtype (65.6%). Of the 109 patients treated surgically, 84 patients (65.6%) underwent limb salvage surgery while the rest underwent amputation. Seventy-one per cent of patients completed treatment with local recurrence rate of 22.7%. The 5-year and 10-year survival rates were 56.31% (95% CI: 46.20, 65.24) and 22.33% (95% CI: 14.86, 30.76), respectively. The 5-year event-free survival was 52.94% (95% CI: 41.83, 62.87). In multivariate analysis, the independent prognostic factors were presence of metastasis and completion of treatment for both 5-year and 10-year overall survival. Good histological response was only significant for multivariate analysis at 5 years. Patients with metastasis had a hazard ratio of 20.4 at 5 years and 3.26 at 10 years. Conclusion: Overall survival rate for osteosarcoma patients at our centre was comparably higher than other centres in the region. Two independent risk factors for survival are metastatic status and completion of treatment. A standardized chemotherapy regime is essential for long-term survival. © The Author(s) 2020

    Comparison of sunlight-driven photocatalytic activity of semiconductor metal oxides of tin oxide and cadmium oxide nanoparticles

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    This study is aimed to investigate the photocatalytic efficiencies of two different metal oxide nanoparticles (NPs), SnO2 and CdO formed by the simple chemical precipitation route. The synthesized metal oxide NPs were examined by several techniques in order to understand the morphological (FESEM), structural (XRD), functional (FTIR), and optical (UV-vis) characteristics. The analysis of results confirmed the successful formation of SnO2 and CdO NPs along with their desired chemical compositions and electronic band structures. Further testing of their photocatalytic efficiency with the use of methylene blue (MB) degradation in the presence of sunlight confirmed their catalytic efficiency. Within the two NPs, the SnO2 has a little higher activity as compared to the CdO NPs and this can be attributed to the increased surface area by means of the formation of nanospheres for the SnO2 ones, while the rod-shaped agglomerated structure with less surface area delaying the rate of degradation. Further from the analysis, it can be confirmed for the superior photocatalytic activity of SnO2 particles having spherical shape against the rod-shaped CdO NPs. © 2020 Elsevier Gmb

    Toxicity comparison among four strains of Margalefidinium polykrikoides from China, Malaysia, and USA (belonging to two ribotypes) and possible implications

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    The unarmored dinoflagellate Margalefidinium polykrikoides is a well-known cosmopolitan harmful alga that forms intensive blooms causing massive fish kills and mortality of other marine animals. Globally distributed populations of M. polykrikoides have been categorized into four ribotypes: East Asian, American/Malaysian, Philippines, and Mediterranean, according to their characteristic sequences in LSU rRNA gene and primary geographic distributions, while no discernible morphological feature has been observed to distinguish. Here we examined the toxicity of four strains of M. polykrikoides including MPJZB-C3 and MPJZB-D6 (East Asian ribotype, from China), CP1 (American/Malaysian ribotype, from USA), and MPCoKK23 (American/Malaysian ribotype, from Malaysia), to three aquatic animals including the marine medaka (Oryzias melastigma), rotifer (Brachionus plicatilis, L-type), and brine shrimp (Artemia salina). With equivalent initial cell densities ranged from 1000 to 7000 cells mL−1, CP1 and MPCoKK23 displayed acute toxicity in a dose-response manner to the three target animals (100% mortality at higher cell densities) within 24 h, MPJZB-C3 also displayed acute toxicity to the fish and rotifer in 24 h (up to 50% mortality) when the cell densities were above 3000 cells mL−1. The strain MPJZB-D6 did not exhibit significant toxicity to all three animals in 24 h, but, in 120 h, caused 50–100% mortalities in fish when the cell density was >3000 cells mL−1 and 17% mortality in brine shrimp when the cell density was >5000 cells mL−1. Statistical analysis of the data indicated that the strains CP1 and MPCoKK23 exhibited significantly higher toxicity (50–100% mortalities) to all three animals than the strains MPJZB-C3 and MPJZB-D6 (0–100% mortality) did within 24 h exposure, while, however, the difference in toxicity between the American and Malaysian strains and that between the two Chinese strains were both not significant in terms of the mortality of test animals. While the cell-free culture media (by filtration) and sonicated cultures were less toxic to test animals than the live cultures for all M. polykrikoides strains, sonicated cultures were even less toxic than the cell-free culture media. Among the three target animals, the marine medaka exhibited most sensitive to the toxicity, followed by rotifer and then brine shrimp. Collectively, while our results demonstrated that all strains, or both ribotypes, of M. polykrikoides are toxic, the results may also suggest the differences in toxicity to three test animals among the four cultures of M. polykrikoides reflect the inherent difference in toxicity between East Asian and American/Malaysian ribotypes, which stimulated us to propose a further investigation on whether or not the four different ribotypes also differ inherently in their toxicity in the future, via comparing more strains of all four ribotypes and relevant genetic characterizations. © 2019 Elsevier B.V

    Can mobile health apps replace GPs? A scoping review of comparisons between mobile apps and GP tasks

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    Background: Mobile health applications (mHealth apps) are increasingly being used to perform tasks that are conventionally performed by general practitioners (GPs), such as those involved in promoting health, preventing disease, diagnosis, treatment, monitoring, and support for health services. This raises an important question: can mobile apps replace GPs? This study aimed to systematically search for and identify mobile apps that can perform GP tasks. Methods: A scoping review was carried out. The Google Play Store and Apple App Store were searched for mobile apps, using search terms derived from the UK Royal College of General Practitioners (RCGP) guideline on GPs' core capabilities and competencies. A manual search was also performed to identify additional apps. Results: The final analysis included 17 apps from the Google Play Store and Apple App Store, and 21 apps identified by the manual search. mHealth apps were found to have the potential to replace GPs for tasks such as recording medical history and making diagnoses; performing some physical examinations; supporting clinical decision making and management; assisting in urgent, long-term, and disease-specific care; and health promotion. In contrast, mHealth apps were unable to perform medical procedures, appropriately utilise other professionals, and coordinate a team-based approach. Conclusions: This scoping review highlights the functions of mHealth apps that can potentially replace GP tasks. Future research should focus on assessing the performance and quality of mHealth apps in comparison with that of real doctors. © 2020 The Author(s)

    Hygro-Thermo-Mechanical Responses of Balsa Wood Core Sandwich Composite Beam Exposed to Fire

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    In this study, the hygro-thermo-mechanical responses of balsa core sandwich structured composite was investigated by using experimental, analytical and numerical results. These investigations were performed on two types of specimen conditions: dry and moisture saturation sandwich composite specimens that are composed of E-glass/polyester skins bonded to a balsa core. The wet specimens were immersed in distilled water at 40 °C until saturated with water. The both dry and wet sandwich composite specimens were heated by fire. The mass loss kinetic and the mechanical properties were investigated by using a cone calorimeter following the ISO 5660 standard and three-point bending mechanical test device. Experimental data show that the permeability and fire resistance of the sandwich structure are controlled by two composite skins. Obtained results allow us to understand the Hygro-Thermo-Mechanical Responses of the sandwich structured composite under application conditions. © 2019 by the authors

    Q-switched and mode-locked erbium-doped fiber laser using gadolinium oxide as saturable absorber

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    Q-switched and mode-locked Erbium-doped fiber lasers (EDFLs) were demonstrated using gadolinium oxide (Gd2O3) as a saturable absorber. The Gd2O3 nano-powder was embedded into polyvinyl alcohol (PVA) film and integrated into the EDFL cavity to achieve both lasers. At first, a stable Q-switched laser was realized at a center wavelength of 1564.1 nm. The repetition rate increased from 78 to 90.74 kHz and the pulse width reduced from 5.68 to 4.68 µs as the pump power adjusted within 96.28 to 147.16 mW. The output power increased steadily from 19.3 to 26.4 mW as the pump power was raised from 96.28 to 147.16 mW. The slope efficiency of the output power was 14%. Later, a 100 m single mode fiber was incorporated into the similar laser cavity to generate a stable mode-locked laser at a threshold pump power of 96.28 mW with a central wavelength of 1561.5 nm. We observed a stable repetition rate of 1.907 MHz with a pulse width of 3.82 ps as the pump power raised from 96.28 to 147.16 mW. The peak power obtained from the mode-locked laser was tunable from 1.78 to 2.58 kW as the pump power was adjusted from minimum to the maximum. These results indicate the outstanding performance of Gd2O3 SA for both Q-switching and mode-locking applications. The lasers are useful for various applications including, micromachining of material, frequency comb-generation and remote sensing. © 2020 Elsevier Inc

    A New Approach for Estimating Insulation Condition of Field Transformers Using FRA

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    Frequency response analysis (FRA) is a tool for evaluating mechanical integrity of transformer's core and winding. However, several studies have reported that FRA is also sensitive to other parameters such as temperature, moisture content and presence of oil. Since some of these parameters are critical in the insulation degradation process, it is interesting to further investigate the possibility of using FRA for insulation assessment. In this paper, the insulation conditions of three field transformers are investigated using FRA. This is performed after statistical analysis on the response suggested no mechanical damage on the transformers. The responses are further analyzed to determine the percentage of change of winding capacitance. This is achieved by comparing resonance frequencies between the responses. The percentage of change represents the amount of degradation in the insulation. This is because as the insulation condition degrades, the response is shifted towards lower frequencies. This new investigation demonstrates the applicability of FRA to estimate the insulation degradation. © 2020 AECE

    The Moderating Effects of Social Media Usage towards Fan Attachment in MotoGP

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    The purpose of this study was to investigate the relationships between MotoGP fans’ attachment with their favorite teams’ Facebook pages. Data were collected through survey method. The questionnaires were completed by 384 fans. Data were analyzed using Statistical Package of Social Science. Sport fans who have formed strong connections to their favorite team may be termed loyal fans. One popular communication tool for such fans is Facebook, which has been found to be an important medium for sharing news and events, yet few studies have examined the moderating of Facebook use in a sport context. Adopting the relational approach examining the determinants of sport-fan attachment, this study examined how Facebook use moderates the building of fan attachment. All independent variables together explain 78 percent of the variance (R Square) in Team Attachment which is highly significant as indicates by the f values 336.845. Findings revealed the t values of team attraction, social media and team involvement are positively related to team attachment. Facebook use was found to significantly reinforce their attachment. Specific implications for both theory and practice are discussed. Overall, respondents indicated they preferred content related to players, including injury and movement, as well as race result, suggesting they might prefer using Facebook as another way to receive information instead of choosing to actively engage with their favorite team. However, because results from modeling suggest engaging individuals on Facebook has positive impacts on future behavioral intentions, sport marketers should consider engaging individuals on Facebook while still fulfilling their need for information about players and game results. © 2020, Hampstead Psychological Associates. All rights reserved

    Seroprevalence of Nipah Virus Infection in Peninsular Malaysia

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    Nipah virus (NiV) outbreak occurred in Malaysia in 1998. The natural host reservoir for NiV is Pteropus bats, which are commonly found throughout Malaysia. Humans become infected when NiV spills over from the reservoir species. In this study, NiV serosurveillance in Peninsular Malaysia, particularly among the indigenous population, was performed. The collected samples were tested for presence of NiV antibodies using a comparative indirect enzyme-linked immunosorbent assay based on the recombinant NiV nucleocapsid (rNiV-N) protein. We found that 10.73% of the participants recruited in this study had antibodies against rNiV-N, suggesting possible exposure to NiV. © The Author(s) 2020. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: [email protected]

    Evaluation of the CO2 emissions of an innovative composite precast concrete structure building frame

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    The type of frame system, materials, and power consumption used for the construction of new buildings cause environmental issues because of the production of carbon dioxide (CO2) emissions. Therefore, a new type of sustainable precast concrete structural system called SMART frame has been introduced to reduce the CO2 emissions during the construction of buildings. To determine the effectiveness of the CO2 emission reduction based on the new SMART frame, a similar frame configuration based on reinforced concrete (RC) was used. The SMART and RC building frames consisted of 12 storeys with similar floor areas and were designed under similar conditions. The CO2 emissions based on the material resources and construction methods used for the two building models were analysed. Additionally, the power consumption associated with the use of electricity and fuels for the devices and equipment was considered in the analysis of the total CO2 emissions. The total CO2 emissions of the SMART and RC frame buildings in kilograms (kg) per square meter (m2) are 455.94 and 516.12 kg CO2/m2, respectively. Thus, the total amount of CO2 emission reduction achieved in this study is 60.18 kg CO2/m2. In terms of the individual effects of materials and power consumption, the SMART building has a larger contribution, accounting for a 12.42% and 8.12% decrease in the CO2 emissions, respectively, compared with the RC building. Overall, based on the materials and power consumption used during the construction stage of the SMART frame building, the total CO2 emissions decreased by 11.66% compared with the RC building. Therefore, the SMART frame can be adopted as a sustainable frame alternative to the RC frame system. © 2019 Elsevier Lt


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